MILK FROTHING DEVICE
There is disclosed herein a frothing assembly (21) to froth milk in a container (11). The assembly (21) includes: a body (25); a motor (33) fixed to the body and having an output shaft (34) that is rotatably driven about a longitudinal axis (35) of the shaft (34); a frothing device (36) rotatably driven by the shaft (34) and to be submerged in the milk in the container (11); and a perforated member (43) at least partly surrounding the frothing device (36) and spaced from the frothing device (36) by a clearance (44), wherein rotation of the frothing device (36) causes movement of milk in the clearance (44) and movement of milk through the perforated member (43) to be circulated back through the container (11) and the clearance (44) to cause frothing of the milk.
This application is a continuation of co-pending U.S. patent application Ser. No. 18/144,286, filed on May 8, 2023, which is a continuation of U.S. patent application Ser. No. 16/762,483, filed May 7, 2020 and issued as U.S. Pat. No. 11,684,033 on Jun. 27, 2023, which is the national stage of International Patent Application No. PCT/AU2018/000215, filed Nov. 7, 2018, which claims priority to Australian Patent Application 2018901605, filed May 10, 2018 and Australian Patent Application 2017904530, filed Nov. 8, 2017, all of which are herein incorporated by reference herein in their entireties.
FIELD OF THE INVENTIONThe present invention relates to milk frothing or texturing and more particularly to mechanical texturing or frothing.
BACKGROUND OF THE INVENTIONTexturing is adding air bubbles to milk. Heated and textured milk is needed to make popular beverages like cappuccino and latte.
The primary benefit of mechanical texturing over steam texturing is the resultant flavour of the milk. Steam tends to add some water into the milk thereby diluting it and the high temperature destroys some of the natural sweetness of the milk. Using a whisk to create a vortex thereby drawing air into the milk arguably has some advantages.
Milk frothing devices are known from the following publications: Foremost B V, Publication US 2012/0017778 (Milk Frother), Aerolatte Limited, patent number U.S. Pat. No. 6,558,035 (Electric Whisk), Chinese patent CN 201683731 (Fully-Automatic Milk Frother), Green Lane Designs, U.S. Pat. No. 8,726,790 (Milk Frothing Device) and Tito Ciusti, GB604048A (Improvement in or related to Pasteurising and boiling apparatus).
A disadvantage of devices that steam textured milk, is that is poor control of the temperature of the milk, while also diluting the milk. A disadvantage of “whisk” type devices is that the milk may not be froth or textured to a desired degree.
OBJECT OF THE INVENTIONIt is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages.
SUMMARY OF THE INVENTIONThere is disclosed herein a frothing assembly to froth milk in a container, the assembly including:
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- a body;
- a motor fixed to the body and having an output shaft that is rotatably driven about a longitudinal axis of the shaft;
- a frothing device rotatably driven by the shaft and to be submerged in the milk in the container; and
- a perforated member at least partly surrounding the frothing device and spaced from the frothing device by a clearance;
- wherein rotation of the frothing device causes movement of milk in the clearance and movement of milk through the perforated member to be circulated back through the container and the clearance to cause frothing of the milk.
Preferably, the frothing device includes a plurality of blades that are spaced angularly about said axis, and that have a direction of extension away from said axis that includes a radial component.
Preferably, the direction of extension also includes an angular component.
Preferably, each of the blades is generally flat.
Preferably, the perforated member has an end portion providing a plurality of passages through which the milk may pass.
Preferably, said end portion is at least partly coextensive with the blades in the direction of said axis.
Preferably, said end portion is substantially coextensive with the blades in the direction of said axis.
Preferably, the frothing device and perforated member provides an assembly that is detachable with respect to the motor.
Preferably, said clearance is annular, and is 0.5 to 1.00 mm.
Preferably, the clearance is about 0.5 mm.
There is further disclosed herein a frother for milk, the frother including a base to support the above container and to which the frothing assembly is attached.
Preferably, the milk frother includes a stem fixed to an extending upwardly from the base, to which the frothing assembly is attached.
Preferably, the frothing assembly is longitudinally adjustable in position on the stem to adjust height of the frothing device relative to the container.
Preferably, the motor is located above the perforated member, with the perforated member extending downwardly from the motor to be at least partly submerged in milk in the container.
Preferably, the base includes a device to heat the milk in the container.
Preferably, the base includes a temperature sensor to detect temperature of the container and therefore the milk.
Preferably, the frother includes circuitry to control the motor and to receive a signal from the sensor, and to control the heater.
Preferably, the circuitry activates the motor to rotate the frothing device at a rotation velocity of about 5,500 rpm to about 13,500 rpm.
Preferably, the circuitry activates the motor to rotate the frothing device at a rotational velocity of about 13,500 rpm for a period, and then at about 9,500 rpm for a further period.
There is further disclosed herein a milk frother to froth milk in a container, the milk frother including:
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- a base assembly for supporting the container, the base assembly including a source of fluid; and
- a frothing assembly attached to the base assembly, the frothing assembly including:
- a body;
- a motor fixed to the body and having an output shaft that is rotatably driven about a longitudinally axis of the output shaft, the output shaft including a hollow channel in communication with the source of fluid;
- a frothing device rotatably driven by the shaft and to be submerged in the milk in the container; and
- a perforated member at least partly surrounding the frothing device and spaced from the frothing device by a clearance, the perforated member being in communication with the hollow channel of the output shaft,
- wherein rotation of the frothing device causes movement of milk in the clearance and movement of milk through the perforated member to be circulated back through the container and the clearance to cause frothing of the milk; and
- whereby the source of fluid is operable to cause fluid to be dispensed through the hollow channel and the perforated member.
There is still further disclosed herein a milk frother to froth milk in a container, the milk frother including:
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- a base assembly having a body to support the container; and
- a frothing assembly at least partially mounted in the body of the base assembly, the frothing assembly including:
- a motor having an output shaft that is rotatably driven about a longitudinally axis of the shaft;
- a frothing device rotatably driven by the shaft and to be submerged in the milk in the container; and
- a perforated member at least partly surrounding the frothing device and spaced from the frothing device by a clearance;
- wherein rotation of the frothing device causes movement of milk in the clearance and movement of milk through the member to be circulated back through the container and the clearance to cause frothing of the milk.
Preferred forms of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:
In
The milk frother 10 includes a base assembly 13 providing a housing 14 within which there is mounted an induction coil 15 to heat the container 11 and milk 12.
Also mounted in the housing 14 is a temperature sensor 16 to detect the temperature of the container 11 (and therefore the milk 12) and provide a signal indicative thereof.
Also mounted in the housing 14 is a user interface 17 that a user may manipulate to control the milk frother 10.
The interface 17 is operatively associated with a microprocessor and control circuitry 18 that operates the induction coil 15 and receives signals generated by the temperature sensor 16.
The circuitry 18 also operates a fan 19 to cause air to flow through the housing 14 to cool componentry located therein.
Supported on a stem 20 fixed to the base assembly 13 is a milk frothing assembly 21. The assembly 21 is also electrically coupled to the circuitry 18 by means of an electric conduit 22, so as to be controlled by the circuitry 18.
The assembly 21 is mounted on the stem 20 so as to be height adjustable in the direction 23 relative to the container 11 resting on the base assembly 13.
The stem 20 (as best seen in
The assembly 21 is attached to the stem 20 by means of a mounting 25. The mounting 25 includes a sleeve 26 that is slidable on the stem 20 in the direction 23. The stem 20 passes through the sleeve 16 so that movement of the mounting 25 slidably along the stem 20 maintains the assembly 21 in the orientation as depicted.
The sleeve 26 has a plurality of threaded apertures 27 that receive a stop member (threaded fastener) 28. The stop member 28 passes through the slot 24, and engages the lower end 29 of the slot 24 to position the assembly 21 at a desired height. This height is adjustable by engagement of the stop member 28 in a selected one of the apertures 27, as the apertures 27 are arranged at different heights, that is different locations in the direction of the slot 24.
The mounting 25 also includes a body 31 extending generally horizontally from the sleeve 26 to which it is affixed.
Pivotally mounted on the body 31 is a catch 30, for angular movement about a generally horizontal axis, that is an axis generally perpendicular to the direction 23 and perpendicular to the stem 20. The catch 30 is angularly movable between a catch position (as shown in
The frothing assembly 21 includes a motor 33 connected to the conduit 22 so as to receive electric power therefrom and to be controlled by the circuitry 18. The motor 33 rotatably drives a shaft 34 about a longitudinal axis 35 of the shaft 34, so as to have a rotational speed of about 5,500 rpm to about 13,500 rpm. The shaft 34 causes operation of a frothing device 36. The frothing device 36 includes a central longitudinal shaft 37 that is provided at its lower end with an impeller 38. In this embodiment the impeller 38 includes a plurality of blades 39 fixed to the shaft 37 so as to rotate therewith. The shaft 37 is fixed to the shaft 34 so as to be driven thereby about the axis 35. The blades 39 are spaced angularly about the axis 35. The device 36 has the same rotational speed as the motor 33. Preferably, the circuitry 18 controls the motor 33 to rotate the shaft 34, and therefore the device 36 at a rotational velocity of about 9,500 rpm for a first period, then at about 13,500 for a second period.
Preferably, the blades 39 have a direction of extension away from the shaft 37 that includes a radial component. More preferably, the blades 39 also have a direction of extension away from the shaft 37 that also includes an angular component. In the longitudinal direction the blades 39 are generally parallel to the axis 35. Preferably the blades are generally planar and inclined to a radius 40 by an acute angle 41. Preferably, the blades 39 are angularly equally spaced about the axis 35.
The impeller 38 is driven in a rotational direction 42 with each blade being inclined in the direction 42 from the adjacent radius 40 by the angle 41.
The frothing assembly 21 includes a perforated member 43 surrounding the impeller 38. In this embodiment, the perforated member 43 is cylindrical in configuration and is spaced from the radially outer extremities of the blades 39 by a clearance 44. Accordingly, there is an annular space 45 surrounding the impeller 38. The member 43 has a lower end portion 82. The member 43 has a lower end portion 82 that has a plurality of radial passages 83 through which the milk flows. However, there is shearing of the milk between the impeller 38 and the member 43 to at least aid in frothing the milk.
In use of the above milk frother 10, the motor 33 is driven at an angular speed of 5,500 rpm, to 13,500 rpm, with the impeller 38 having four blades 39. The container 11 is cylindrical in configuration so as to have a diameter 46, with the milk having a depth 47. Preferably, the lower end extremity of the frothing device 36 is spaced from the base 48 of the container 11 by a depth 49. Preferably, the member 43 has a diameter 50 and the impeller 38 a diameter 51. Preferably, the blades 39 have a longitudinal length 52 in the direction 23. The blades 39 are generally co-extensive with the portion 82 in the direction of the axis 35.
Preferably, the depth 47 is approximate the internal diameter 46. Preferably, the length 52 is ¼ to ⅙ of the diameter 51. Preferably, the depth is ½ to ⅙ of the depth 47. Preferably, the diameter 51 is a four to eight times the clearance 44 and most preferably about six times the clearance 44. Preferably, the clearance 44 is about .5 to about 1.00 mm, most preferably about, 5 mm. Preferably, the angle 41 is 20° to 30° and most preferably about 25°.
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The fluid pump 185 is connected to the source of fluid (i.e. the fluid tank 186 or the mains fluid supply) and the fluid sensor 187. Fluid is added to the fluid tank 186 via an opening (not shown) in the housing 114. The circuitry 118 also operates the fluid sensor 187 to detect the amount of fluid within the fluid tank 186 and alerts the user, via the user interface 117, if the amount of fluid detected is low.
The circuitry 118 operates the air pump 188 to draw air from an opening (not shown) in a side wall of the housing 114. The air pump 188 is connected to the air pressure sensor 189 to detect the amount of air that is being drawn into the air pump 188. It is envisaged that the circuitry 118 may additionally include other forms of sensors, such as a speed sensor to detect a motor speed of the air pump 188 and predict the amount of air that is being drawn into the air pump 188.
The fluid pump 185 is connected to a hollow channel 192 of the central longitudinal shaft 137 of the frothing device 136 by way of a fluid conduit 193. The hollow channel 192 includes an opening connected to the impeller/rotor 138. The air pump 188 is also connected to the hollow channel 192 by way of an air conduit 194. Following use of the milk frother 100, the circuitry 118 operates the fluid pump 185 and the air pump 188 to pump fluid and air (either separately or simultaneously) into the hollow channel 192, so as to purge and thereby clean the internal and external surfaces of the impeller/rotor 138. It will be appreciated that in other embodiments (not shown), the hollow channel 192 of the central longitudinal shaft 137 is connected directly to the source of fluid (e.g. directly to the fluid tank 186 or to the mains fluid supply via a manually operable valve). When connected to the mains fluid supply, the valve may be operable to introduce fluid from the mains fluid supply into the hollow channel 192 to purge and thereby clean the internal and external surfaces of the impeller/rotor 138.
It will be appreciated that the control of the fluid sensor 187, the pressure sensor 189, the fluid pump 185 and the air pump 188 is facilitated by the switches 190 and 191.
In the embodiment of
In
In
The inner container 198c includes a base 198f and a plurality of base protrusions 198g extending upwardly from the base 198f. The plurality of base protrusions 198g are engageable with the impeller 138 of the frothing device 136. Engagement of the base protrusions 198g and operation of the impeller 138 causes the inner container 198c to also rotate about the longitudinal axis 135 of the shaft 134. The rotation causes friction between the protrusions 198d and the perforated member 143, whereby the protrusions 198d act in a similar manner to bristles on a brush. This action, in conjunction with the agitation of the fluid within the inner and outer containers 198c and 198a, facilitate the cleaning of the internal and external surfaces of the impeller 138.
The frothing assembly 221 includes a motor 233 which rotatably drives a shaft 234 about a longitudinal axis 235 of the shaft 234, so as to have a rotational speed of about 5,500 to 13,500 rpm as with the milk frothers 10 and 100 described above. An impeller 238 is coupled to the shaft 234 so as to be driven thereby about the axis 235. The impeller 238 includes a plurality of protrusions 239 spaced angularly about the axis 235.
In this embodiment, the base 201 of the container 211 includes a channel 202 formed therein. The channel 202 is defined by a hollow space surrounded by a cylindrical wall 203 having outer screw threads 204 formed at an upper end thereof. The milk frother 200 includes a perforated member 243 having inner screw threads 205 which correspond to the outer screw threads 204 of the channel 202, thereby allowing the perforated member 243 to be screwed onto the channel 202 of the container 211. The hollow space of the channel 202 accommodates the impeller 238. Attached to the impeller 238 is an agitator member 206 having protrusions 207 that correspond to the protrusions 239 of the impeller 238 so as to provide a snug fit therebetween. Also coupled to the impeller 238 is a bearing 208 and washers 209 to provide balance and structural integrity to the impeller 238 and agitator member 206 whilst the shaft 234 is driven to rotate.
As best shown in
Claims
1. A frothing assembly to froth milk in a container, the assembly including:
- a body;
- a motor fixed to the body and having an output shaft that is rotatably driven about a longitudinal axis of the shaft;
- a frothing device rotatably driven by the shaft and to be submerged in the milk in the container; and
- a perforated member at least partly surrounding the frothing device and spaced from the frothing device by a clearance,
- wherein rotation of the frothing device causes movement of milk in the clearance and movement of milk through the perforated member to be circulated back through the container and the clearance to cause frothing of the milk.
2. The frothing assembly of claim 1, wherein the frothing device includes a plurality of blades that are spaced angularly about said axis, and that have a direction of extension away from said axis that includes a radial component.
3. The frothing assembly of claim 2, wherein the direction of extension also includes an angular component.
4. The frothing assembly of claim 2 or 3, wherein each of the blades is generally flat.
5. The frothing assembly of any one of claims 1 to 4, wherein the perforated member has an end portion providing a plurality of passages through which the milk may pass.
6. The frothing assembly of claim 5, wherein said end portion is at least partly coextensive with the blades in the direction of said axis.
7. The frothing assembly of claim 5, wherein said end portion is substantially coextensive with the blades in the direction of said axis.
8. The frothing assembly of any one of claims 1 to 7, wherein the frothing device and perforated member provides an assembly that is detachable with respect to the motor.
9. The frothing assembly of any one of claims 1 to 8, wherein said clearance is annular, and is 0.5 to 1.00 mm.
10. The frothing assembly of claim 9, wherein the clearance is about 0.5 mm.
11. A frother for milk, the frother including a base to support the above container and to which the frothing assembly of any one of claims 1 to 10 is attached.
12. The frother of claim 11, further including a stem fixed to an extending upwardly from the base, to which the frothing assembly is attached.
13. The frother of claim 12, wherein the frothing assembly is longitudinally adjustable in position on the stem to adjust height of the frothing device relative to the container.
14. The frother of any one of claims 11 to 13, wherein the motor is located above the perforated member, with the perforated member extending downwardly from the motor to be at least partly submerged in milk in the container.
15. The frother of any one of claims 11 to 14, wherein the base includes a device to heat the milk in the container.
16. The frother of any one of claims 11 to 15, wherein the base includes a temperature sensor to detect temperature of the container and therefore the milk.
17. The frother of claim 15 or 16, further including circuitry to control the motor and to receive a signal from the sensor, and to control the heater.
18. The frother of claim 17, wherein the circuitry activates the motor to rotate the frothing device at a rotation velocity of about 5,500 rpm to about 13,500 rpm.
19. The frother of claim 18, wherein the circuitry activates the motor to rotate the frothing device at a rotational velocity of about 13,500 rpm for a period, and then at about 9,500 rpm for a further period.
20. A milk frother to froth milk in a container, the milk frother including:
- a base assembly for supporting the container, the base assembly including a source of fluid; and
- a frothing assembly attached to the base assembly, the frothing assembly including: a body; a motor fixed to the body and having an output shaft that is rotatably driven about a longitudinally axis of the output shaft, the output shaft including a hollow channel in communication with the source of fluid; a frothing device rotatably driven by the shaft and to be submerged in the milk in the container; and a perforated member at least partly surrounding the frothing device and spaced from the frothing device by a clearance, the perforated member being in communication with the hollow channel of the output shaft, wherein rotation of the frothing device causes movement of milk in the clearance and movement of milk through the perforated member to be circulated back through the container and the clearance to cause frothing of the milk; and whereby the source of fluid is operable to cause fluid to be dispensed through the hollow channel and the perforated member.
21. A milk frother to froth milk in a container, the milk frother including:
- a base assembly having a body to support the container; and
- a frothing assembly at least partially mounted in the body of the base assembly, the frothing assembly including: a motor having an output shaft that is rotatably driven about a longitudinally axis of the shaft; a frothing device rotatably driven by the shaft and to be submerged in the milk in the container; and a perforated member at least partly surrounding the frothing device and spaced from the frothing device by a clearance;
- wherein rotation of the frothing device causes movement of milk in the clearance and movement of milk through the member to be circulated back through the container and the clearance to cause frothing of the milk.
Type: Application
Filed: Jun 12, 2024
Publication Date: Oct 3, 2024
Inventors: Duncan Bruce HELLMERS (Alexandria), Giovanni BAEZ (Alexandria), Norman OLIVERIA (Alexandria), Gerard WHITE (Alexandria)
Application Number: 18/740,643